The present invention provides a new and improved method and apparatus for use in inspecting recesses formed in airfoils.
Airfoils have previously been formed with locating recesses in opposite sides of a root portion of each airfoil. The recesses are drilled after the airfoil is cast. After the recesses have been drilled, the airfoil may be sent to a customer for further machining. The recesses are used to locate the airfoil during machining by the customer.
In the past, a substantial percentage of the airfoils have been rejected by a customer due to inaccurately formed locating recesses. The recesses must have a substantially perfect geometry after being formed with a drill. A drill which has been worn even slightly, for example, by an amount which is undetectable by visual inspection of the drill, may form recesses which are not acceptable to the customer as a datum for further machining operations.